One of my favorite garden tasks is dividing perennials. It reminds me of a buy one, get one free sale. I start with one plant and wind up with 2, or more, for free!
There are other reasons for dividing perennials. Some need to be rejuvenated while others have grown too large for their garden niche.
Herbaceous perennials, unlike woody shrubs and trees, can be divided because they have very flexible stems. These stems and the leaves die in winter. The only part of the plant that remains alive is underground.
While many perennials can be divided (some can’t), it tends to be hard on some of them. It may take them several years to fully recover. Others, like black-eyed Susan (Rudbeckia hirta), don’t mind at all.
Conduct a background check
Before you divide a plant, you may want to conduct a quick background check. Does it like to be divided? If so, when? What type of soil does it prefer? Acidic, basic or neutral? Here are some general tips to help you get started:
Plants tend to get divided in the opposite season in which they bloom:
- In the fall, divide spring blooming perennials.
- In the spring, divide fall blooming plants.
Some plants,
like native Bee balm (Monarda), can be divided in the spring or fall. Beebalm is divided every three years to control its growth.
Some plants never get divided after they are first planted — they just don’t like being moved and may die if they are. Examples of this are butterfly weed (Asclepias), false indigo (Baptisia) and columbine (Aquilegia).
Create an inviting bed
Be sure to prepare a hospitable home for newly divided perennial. Improve the soil with peat moss, compost or manure prior to planting. Keep the plant’s roots moist until they are planted.
Need more information?
For more information about dividing herbaceous perennials, here are three excellent websites:
The University of Maryland (UMD) Extension:
https://extension.umd.edu/learn/dividing-herbaceous-perennials-hg99
The Montgomery Master Gardeners, UMD Extension:
The Clemson University Extension:
http://www.clemson.edu/extension/hgic/plants/landscape/flowers/hgic1150.html
Happy dividing!
Laura